1. Field of the Invention
This invention relates to a connection structure for coaxial connectors wherein the relative positions of opposing coaxial connectors are displaceable in a direction perpendicular to the opposing direction, and particularly to an adapter for use in connecting such coaxial connectors.
2. Description of the Related Art
Conventionally, as a connection structure for coaxial connectors, a connection structure for a coaxial connector and an electronic circuit unit is disclosed in Japanese Patent Laid-Open Application No. Showa 57-205978 wherein a male connection screw is attached to a housing of a coaxial connector having a central conductor while a case of an electronic circuit unit to be connected to the coaxial connector includes a female screw with which the connection screw is to be screwed, and a coaxial terminal having a central conductor to be coupled to the coaxial connector concentrically with the female screw. Meanwhile, Japanese Patent Publication Application No. Heisei 3-6681 discloses another connection structure for coaxial connectors wherein at least one of a plug side central conductor and a jack side central conductor is supported by a cantilever support structure having a free end on the fitting side thereof and a gap is provided between an outer periphery of a fitting portion of a plug side outer conductor and an inner periphery of a fitting portion of a jack side outer conductor. Those connection structures for coaxial connectors connect coaxial lines to each other in a small space.
By the way, for connection of a transmitter-receiver board to a communication apparatus, a structure shown in FIG. 1 is known. Referring to FIG. 1, a transmitter-receiver 120 including a case in which a transmitter-receiver circuit formed as a unit is accommodated is secured to a transmitter-receiver board 110. The transmitter-receiver 120 includes a plurality of coaxial connectors 140 provided thereon for connecting a communication apparatus (not shown) and the transmitter-receiver 120 to each other when the transmitter-receiver board 110 is mounted on the communication apparatus.
The position of the coaxial connector on the communication apparatus side with respect to the mounted position of the transmitter-receiver board 110 depends upon the type of the communication apparatus. Therefore, in order to provide the transmitter-receiver board 110 with universality, a coaxial connector housing 130 having a plurality of coaxial connectors 150 to be connected individually to the coaxial connectors 140 of the transmitter-receiver 120 with coaxial cables 160 interposed therebetween is provided on the transmitter-receiver board 110 so that the position thereof can be adjusted in the direction indicated by an arrow A. The coaxial connectors 150 of the coaxial connector housing 130 are connected to the coaxial connector of the communication apparatus.
Since the coaxial cables 160 are used for connection of the coaxial connectors 140 of the conventional transmitter-receiver board 110 described above, in order to allow adjustment of the position of the coaxial connector housing 130, the coaxial cables 160 must have a sufficient length to allow the coaxial cables 160 to be connected in individually curved conditions. However, the lowest value of the radius of curvature of the coaxial cables 160 is limited by the rigidity of the coaxial cables 160. Therefore, some space is required between the coaxial connector housing 130 and the transmitter-receiver 120, and this presents an obstacle to miniaturization of the transmitter-receiver board.
A possible countermeasure to solve this is to apply the structure disclosed in Japanese Patent Laid-Open Application No. Showa 57-205978 or Japanese Patent Publication Application No. Heisei 3-6681. However, since the structure disclosed in Japanese Patent Laid-Open Application No. Showa 57-205978 relates to a connection between a coaxial cable and an electronic circuit unit, one cannot still avoid to employing a coaxial cable for connection between the coaxial connectors, and therefore the structure does not provide a fundamental solution. Meanwhile, with the structure disclosed in Japanese Patent Publication Application No. Heisei 3-6681, even if the opposing positions of two coaxial connectors are displaced relative to each other, the central conductor supported in the form of a cantilever is distorted in a radial direction so that the two coaxial connectors can be connected to each other without a coaxial cable interposed therebetween. However, since the displacement between the opposing positions of the coaxial connectors is absorbed making use of the distortion of the central conductor in this manner, the allowable amount of displacement is approximately several tenth mm. Accordingly, the structure cannot absorb a large amount of displacement.